US3592259A

US3592259A - Cooling means for a continuous casting mold assembly

Info

Publication number: US3592259A
Application number: US782646A
Authority: US
Inventors: Alfred Adamec; Roland Leder; Walter Fadler
Original assignee: Wiener Schwachstromwerke GmbH
Current assignee: Wiener Schwachstromwerke GmbH
Priority date: 1967-12-15
Filing date: 1968-12-10
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13
Also published as: GB1247376A; DE1814647A1; AT276655B; CH488506A; FR1598396A; ES361380A1; DK121323B

Abstract

A graphite mold for use in continuous casting operations is cooled by elements mounted on the side faces and at the outlet end face of the mold. A plurality of the cooling elements are provided on the exterior of the mold to afford a variable cooling effect for the member being cast within the mold. An attachment device positively and detachably mounts the cooling elements on the graphite mold.

Description

United States Patent Inventors Appl. No. Filed Patented Assignee Priority COOLING MEANS FOR A CONTINUOUS CASTING MOLD ASSEMBLY 5 Claims, 1 Drawing Fig.

11.8. C1 164/283, 164/138 Int. Cl B2211 11/00 Field of Search 164/82, 138, 273, 283, 348

: a r I I0 Primary Examiner-R. Spencer Annear Attorney-McGlew and Toren ABSTRACT: A graphite mold for use in continuous casting operations is cooled by elements mounted on the side faces and at the outlet end face of the mold. A plurality of the cooling elements are provided on the exterior of the mold to afford a variable cooling effect for the member being cast within the mold. An attachment device positively and detachably mounts the cooling elements on the graphite mold.

PATENTEB JUL 13 L9H QM PM w 7n W MOI R ATTORNEY 5 COOLING MEANSFOR A CONTINUOUS CASTING MOLD ASSEMBLY SUMMARY OF THE INVENTION In the continuous casting of noble metals and, especially,

when such metals are being cast in strip form, care must be exercised that the speed at which the strip is withdrawn from the casting mold is varied depending on the thickness dimension and the thermal conductivity of the metal casting being formed. In many instances, uncontrolled cooling results in a casting which is in'a pasty or plastic condition as it issues from the mold or, where intense back-cooling exists within the mold, the molten material solidifies close to the inlet end of the casting mold and, as a result, cannot be withdrawn from the mold or the casting lacks dimensional consistency. Ac-. cordingly, his not possible to use the same molding assembly for casting materials having widely different solidification points in a continuous casting operation. In the past, to overcome this problem, either difi'erent cooling elements or different molds or a combination of the two was utilized for continuously casting molten material.

Graphite molds used in continuous casting operations are inherently soft and, when alteration or adjustment was required during operation the molds often were destroyed during changeover. Further, graphite molds are highly expensive because they must be machined to close tolerances. Moreover, graphite molds have a relatively short working life, which often amounts to only one working day, and as a result, the inherently desirable continuous casting process achieved by using graphite molds is not as advantageous as the usual rolling processes.

Therefore, it is a primary object of the present invention to overcome the disadvantages experienced in the use of graphite molds in the past and to provide a suitable cooling arrangement for a graphite mold which is adaptable for use with various casting materials.

Accordingly, the present invention is directed to a device comprised of a multiple number of cooling elements consisting of at least one cooling element located at the outlet end of the mold and several cooling elements located along the sides of the mold intermediate its inlet and outlet ends. Another feature of the invention is the employment of an attachment device for positively and detachably securing the cooling elements to the graphite mold.

The positive connection of the side cooling elements to the graphite mold is accomplished by providing tapered surfaces on the graphite mold with similarly inclined faces on the cooling elements with the juxtaposed faces of the mold and the cooling elements being forced into contact with one another by the connection means.

The cooling effect is achieved preferably by means of conduits or bores within the cooling elements throughwhich a cooling medium is circulated. The conduits or cooling medium flow passageways extend about the casting space within the graphite mold for the length of the cooling elements. In different elements, the diameters of the passagewaysmay be varied and the spacing from the casting space to the passageways also can be varied for affording different cooling effects. Further, the flow cooling mediumxto the passageways can be independently supplied and regulated with the same or different cooling mediums being circulated through the'flow passageways in the individual cooling elements.

Where a plurality of cooling medium flow passageways are located in the cooling elements at theoutlet end of the continuous casting mold, one flow passageway can contain a primary cooling medium for indirect cooling of the casting while another cooling element circulates a secondary cooling medi um for direct cooling of the casting, such as by blowing the cooling medium directly against the surface of the casting as it exits from the mold.

To afford effective regulating of the cooling of the casting as it passes through the graphite mold, it is desirable to provide thermal separation of the cooling elements and to construct them from different materials having different thermal conductivities. By proper selection of the materials in the cooling elements and the cooling medium circulated through 'their flow passageways, it is possible to achieve an exact control of the location of the solidification range of the casting as it is formed within the mold.

The various features of novelty which characterize the in vention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawing and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the Drawing:

The drawing is a cross-sectional view through a continuous casting mold and cooling device embodying the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, a graphite mold 1 is shown having a casting space la extending from an inlet end 1b to an outlet end 1c. .Theexterior or peripheral surfaces 1d of the mold taper outwardly from the inlet to the outlet end of the mold. In surface contact with the exterior surfaces 1d of the mold are a pair of retaining elements 2 whose internal surfaces 2d are tapered to conform to the juxtaposed surfaces 1d of the mold.

At the outlet end 10 of the mold, a cooling device 3 is provided in contact with the end surface and the device has a passageway 3c in axial alignment with the casting space la within the mold. The cooling device 3 may be formed'of one or more cooling elements.

During assembly, the graphite mold l is inserted into the I retaining elements 2 to force the tapered surfaces on each into closely fitting contact, A yoke 4 is located on the surface of the cooling member 3 spaced outwardly from the graphite mold and interconnects the retaining elements 2. Screws 5 adjustably bear on the yoke 4 and force a pressure plate 6 against the cooling device for securing it in position at the outlet end of the graphite mold l and assure the closely fitting contact between the retaining elements 2, the cooling device 3, and the mold 1.

In the embodiment shown in the drawing, the cooling device 3 is formed of'two

end cooling elements

3a, 3b which can'be made of metals or other substances having either the same or different thermal properties. Cooling medium flow passageways are provided by means of conduits 7 located in the cooling element 3b and conduits 8 located in cooling element 3a. The conduits 7 provide a primary coolant system for the casting at the outlet end of the mold and the conduits 8 provide a secondary coolant system. As indicated in the draw ing, the cross-sectional dimension of the conduits 7 is greater than that of the conduits 8. Further, passageways 8a extend from theconduit 8 to the end of the passage 36 situated at its end opposite the outlet from the graphite mold.

The primary coolant system affords an indirect'cooling effect on the continuous casting issuing from the graphite mold l, and effects a recooling and solidification of the casting; The secondary coolant system provides a flow of a coolingmedium, such-as an inert gas, oxygen, water and the like, which streams through the conduits 8 and passageways 8i1'o'nto the surface of the casting as it issues from the passage3c through the cooling device 3. Due to the differences between the thermal conductivities of metals being molded in the continuous mold. The position of the transition point determines the most economical withdrawal speed for removing the casting from the mold.

in accordance with the invention, the retaining devices 2 provide a cooling effect on the faces or exterior surfaces-1d of the mold and are constructed of a plurality of

cooling elements

2a, 2b, and 2c which are thermally separate. The

cooling elements

2a, 2b, and 2c are preferably formed of different materials and each contains a conduit 9 forming a coolant passageway with the diameter of the passageways. varying between-the cooling elements. Moreover, due to the configuration of the graphite mold and the structure of the cooling elements, the spacing between the centerline of the casting space In within the mold and the conduits 9 varies from cooling element to cooling element. The flow passageways formed by the conduits 9 can be arranged to receive the same or different cooling mediums and valves 10 are provided in each line for separately or jointly shutting off the supply of the coolant medium into the flow passageways. While the conduits 9, forming the flow passageways for the cooling medium or mediums, are indicated in the drawing as extending transversely to the axis of the casting space through the mold, it should be understood that the conduits also may be arranged in the longitudinal or the diagonal direction or in a combination of these directions for affording the optimum cooling efiect on the casting within the graphite mold.

7 Depending on the properties of the metals passing through the graphite mold in the continuous casting operation, the

can be effected to maintain the transition region at the one position within the graphite mold.

"We claim: l. A 'graphite mold assembly for continuous casting operations, such as continuous strip casting, comprising a graphite supply of cooling medium into the various flow passageways end face providing aN inlet to and the other end face an outletfrom the casting space and side faces extendingbetweens'aid end'faces with said side faces disposed in diverging i'elation-v ship from theinlet end face to the outlet end face, said cooling device comprising a cooling member disposed in contacting relationship with the outlet end face of said mold, a retaining device having surfaces conforming to the shape of and disposed in contacting relationship with the side faces of said mold,-and means for providing closely fitting contact between said mold and said cooling member and retaining device, said retaining device comprising a plurality of separate first cooling elements each in contact with the side faces of said mold, said cooling member having a passageway therethrough in alignment with and forming a continuation of the casting space to said mold for conveying continuous castings from said mold, said cooling member comprising a plurality of second cooling elements disposed about the passageway through said cooling member, said first and second cooling elements having passageways for circulating a cooling medium therethrough, and means for regulating the flow of cooling medium through said first and second cooling elements whereby a variable cooling effect for the continuous casting processed through said mold can be obtained.

2. In a graphite mold assembly, as set forth in claim 1, wherein said means for providing closely fitting contact comprising a yoke mounted against the surface of said cooling member remote from the outlet end face of said mold, adjustable screws engaged with said yoke for varying the pressure exerted by said yoke on said cooling member and mold for effecting the closely fitting contact.

' v 3. A graphite mold assembly, as set forth in claim 1, wherein the passageways in said first cooling elements each having a different cross-sectional area and the distance from the centerline of said casting space to each of the passageways being different.

4. A graphite mold assembly, as set forth in claim 1, wherein said means for regulating the flow of cooling medium comprising' a valve positioned in each of the passageways in said first and second cooling elements for effecting independent regulation of the circulation of the cooling medium through the passageways.

5. A graphite mold assembly, as set forth in claim 1, wherein

Claims

1. A graphite mold assembly for continuous casting operations, such as continuous strip casting, comprising a graphite mold and a multipart cooling device detachably connected to said mold, wherein the improvement comprises said mold forming a casting space therein for the passage of a casting therethrough, said mold having oppositely directed spaced end faces intersected by the passage therethrough with one end face providing aN inlet to and the other end face an outlet from the casting space and side faces extending between said end faces with said side faces disposed in diverging relationship from thE inlet end face to the outlet end face, said cooling device comprising a cooling member disposed in contacting relationship with the outlet end face of said mold, a retaining device having surfaces conforming to the shape of and disposed in contacting relationship with the side faces of said mold, and means for providing closely fitting contact between said mold and said cooling member and retaining device, said retaining device comprising a plurality of separate first cooling elements each in contact with the side faces of said mold, said cooling member having a passageway therethrough in alignment with and forming a continuation of the casting space to said mold for conveying continuous castings from said mold, said cooling member comprising a plurality of second cooling elements disposed about the passageway through said cooling member, said first and second cooling elements having passageways for circulating a cooling medium therethrough, and means for regulating the flow of cooling medium through said first and second cooling elements whereby a variable cooling effect for the continuous casting processed through said mold can be obtained.

3. A graphite mold assembly, as set forth in claim 1, wherein the passageways in said first cooling elements each having a different cross-sectional area and the distance from the centerline of said casting space to each of the passageways being different.

4. A graphite mold assembly, as set forth in claim 1, wherein said means for regulating the flow of cooling medium comprising a valve positioned in each of the passageways in said first and second cooling elements for effecting independent regulation of the circulation of the cooling medium through the passageways.

5. A graphite mold assembly, as set forth in claim 1, wherein said first and second cooling elements are formed of materials having different characteristics of thermal conductivity for varying the cooling on the casting being processed through said mold.